CNC machine tools are generally composed of input and output devices, numerical control devices, programmable controllers, servo systems, detection and feedback devices, and machine tools.
1.Input and output devices
The input device can transmit different processing information to the computer. In the early days of the production of CNC machine tools, the input device was perforated paper tape, which has tended to be eliminated. At present, the use of keyboards and magnetic disks greatly facilitates information input.
Output refers to the output of internal working parameters (including the original parameters of the machine under normal and ideal working conditions, fault diagnosis parameters, etc.). Generally, these parameters need to be output for record keeping when the machine is just working. After working for a period of time, the output and original The comparison and comparison of the data can help judge whether the machine tool works normally.
2. Numerical control device
The NC device is the core and leading of the NC machine tool, completes the processing and calculation of all processing data, and finally realizes the command of the functions of the NC machine tool. It contains the microcomputer circuit, various interface circuits, CRT monitor and other hardware and corresponding software.
That is, PLC, which controls the spindle unit, processes the speed instructions in the program to control the spindle speed; manages the tool magazine, performs automatic tool exchange, tool selection methods, cumulative tool usage times, tool remaining life and tool sharpening times, etc. Management; control the forward and reverse rotation and stop of the spindle, exact stop, cutting fluid switch, chuck clamping release, robot picking and feeding, etc .; also control external switches of the machine tool (stroke switch, pressure switch, temperature control switch, etc.) ; Control the output signals (tool magazine, robot, rotary table, etc.).
4. Detection and feedback device
It consists of a detection element and a corresponding circuit, which mainly detects the speed and displacement, and feeds back the information to the NC device to implement closed-loop control to ensure the machining accuracy of the NC machine tool.
5. Machine tool host
The main body of the CNC machine tool includes mechanical parts such as the bed, the main shaft, and the feed transmission mechanism.